1. Field of the Invention
The present invention relates to a Thin Film Transistor (TFT) and a flat panel display including the TFT, and more particularly, to a TFT that reduces leakage current and prevents crosstalk between adjacent TFTs, and a flat panel display including the TFT.
2. Description of the Related Art
Thin Film Transistors (TFTs) used in liquid crystal displays, organic electroluminescent displays, or inorganic electroluminescent displays are used as switching devices to control the operation of each pixel or driving device for driving the pixel.
A TFT includes a source electrode and a drain electrode separated from each other, a semiconductor layer having a channel region formed between the source and drain electrodes, and a gate electrode insulated from the source electrode, the drain electrode, and the semiconductor layer.
When TFTs having the above structure are formed in an array, each of the TFTs operates as an independent switching device. The semiconductor layer can be patterned to prevent crosstalk between adjacent TFTs. For example, in the case of a conventional TFT, the semiconductor layer formed of silicon is patterned using a photolithgraphy method.
On the other hand, many attempts have been made to use a plastic substrate instead of a conventional glass substrate in a flexible display. The conventional silicon TFT can not be used since the plastic substrate can not be processed at a high temperature.
Therefore, methods of forming a TFT on a plastic substrate at a low temperature have been proposed. Particularly, many studies regarding a TFT that can be processed at a low temperature, that is, a TFT in which the semiconductor layer is formed of an organic material, have been undertaken. However, in the case of the organic TFT, the organic semiconductor layer cannot be patterned using the conventional photolithography method. That is, when the organic semiconductor layer is patterned using a conventional wet, dry, or mixed etching process, the organic semiconductor layer can be damaged, and thus, it cannot be used.